I initially tried to order on Store.Apple.com at 1:15am PST. The message "Processing Information... " sat spinning for an hour and one-half.
Seeing that was not productive, I logged into my AT&T account. It processed my order immediately, confirming I get to keep the $30/mo unlimited data plan and promising free overnight shipping on the 24th -- maybe.
So at that point, I aborted the Apple Store attempt.
Then when I tried to return to the Apple Store to see the custom options on the new Mac mini, the store was down. That was two hours ago and it's still down as of 5:39am PST.
I'm not surprised to see flames shooting out of my screen when I visited this iPhone forum.